var a = [1,2,3];
a.unshift(5);
console.log(a);

var b = [1,2,3];
b.shift();
console.log(b);

var c = ['wd','nm','d'];
c.sort();
console.log(c);

var d = [444,458,74747];
d.reverse();
console.log(d);

var e = ['ai','nan','shou','xiang','gu'] 
e.splice(1,2,'dn','made')   
console.log(e)

var f = ['bf','cod','ttf']
f.splice(1,1)   
console.log(f)

var g = ['ssss','atm','watchdogs']
g.splice(1,0,'ss','aidehua')    
console.log(g)